A Transitional Behavior of a Premixed Flame and a Triple Flame in a Lifted Flame(II)

In the paper we investigate characteristics of a transitional behavior from a premixed flame to a topic flame in a lifted flame according to the change of equivalence ratio in previous study, we showed that the stabilized laminar lifted flame regime is categorized by regimes of premixed flame, triple flame and critical flame A gas-chromatograph is used to measure concentration field, a smoke-wire system is used to measure streak line, and a PIV system is used to measure velocity field in lifted flame in the visualization experiment of smoke wire, the flow divergence and redirection reappeared in premixed flame as well as triple flame Thus we cannot express the flame front of lifted flame has a behavior of triple flame with only flow divergence and reduction in PIV measurement, flow velocity for those three flames has minimum value at the tip of flame front. To differentiate triple flame and premixed flame, φ value of partially premixed fraction is employed The partially premixed fraction φ was constant in premixed flame in critical flame small gradient appears over the whole regime. in triple flame, typical diffusion flame shape is obtained as parabolic distribution type due to diffusion flame trailing.